Should I Take Cod Liver Oil or Omega 3 Supplements?

January 13, 2026 •

2 min read

According to the National Institutes of Health, over 7% of US adults use fish oil supplements. When considering these supplements, a common question arises: should I take cod liver oil or omega 3? While both contain beneficial fatty acids, their source and additional nutrients differ significantly, influencing which is best for you.

Quick Summary

Cod liver oil is a source of omega-3s with added vitamins A and D, while standard omega-3 supplements contain higher concentrations of EPA and DHA from fatty fish. Your choice depends on your specific nutritional goals and whether you need extra vitamins.

Key Points

Cod liver oil includes vitamins: Unlike pure omega-3 fish oil, cod liver oil is a natural source of significant vitamins A and D in addition to omega-3 fatty acids.
Omega-3 potency differs: Omega-3 fish oil supplements often contain a higher, more concentrated dose of EPA and DHA compared to cod liver oil, which has a lower omega-3 concentration due to its vitamin content.
Consider vitamin A toxicity: High doses of cod liver oil can lead to vitamin A toxicity over time, making it less suitable for long-term, high-dose usage, especially for pregnant women.
Targeted benefits vary: Choose cod liver oil for combined support for bones, immune function, and vision, or a concentrated omega-3 supplement for focused cardiovascular and cognitive benefits.
Source matters: Cod liver oil comes specifically from cod livers, while omega-3 fish oil can be sourced from various fatty fish like salmon and mackerel.
Consult a professional: Always speak with a doctor before starting a new supplement, especially if you are pregnant, breastfeeding, or on blood-thinning medication.

Understanding the Core Difference: Source and Composition

Cod liver oil comes from the liver of codfish and contains omega-3 fatty acids (EPA and DHA) along with vitamins A and D. Omega-3 supplements, or regular fish oil, are typically from the flesh of various fatty fish and are processed for higher concentrations of EPA and DHA without significant amounts of vitamins A and D.

Cod Liver Oil: A Nutrient-Rich Tradition

Historically used for various ailments, cod liver oil is valued for providing both omega-3s and fat-soluble vitamins, particularly vitamin D which is important for those with limited sun exposure. It may help with rheumatoid arthritis pain and swelling, support bone strength, aid immune function, and contribute to eye health due to vitamins A and D and DHA.

Omega-3 Supplements: Potency and Purity

Omega-3 fish oil supplements offer a more concentrated dose of EPA and DHA. Processing refines the oil, increasing potency and reducing potential contaminants and vitamin levels, which can help mitigate the risk of vitamin A toxicity associated with high-dose cod liver oil. These supplements may support heart health by potentially lowering triglycerides and blood pressure, aid cognitive function (DHA), and provide anti-inflammatory effects.

Cod Liver Oil vs. Omega-3: A Comparative Table


Feature	Cod Liver Oil	Omega-3 Fish Oil	Which is Better?
Source	Liver of codfish	Flesh of fatty fish (mackerel, salmon)	Depends on nutrient needs
Omega-3 Concentration	Lower (contains vitamins A/D)	Higher (concentrated EPA/DHA)	Omega-3 for specific EPA/DHA goals
Vitamins	Contains significant vitamins A & D	Contains negligible vitamins A & D	Cod liver oil for combined nutrient needs
Toxicity Risk	Higher risk of vitamin A toxicity with high doses	Very low risk of vitamin toxicity	Omega-3 for long-term high-dose use
Use Case	General wellness, bone health, immune support	Cardiovascular health, brain function, targeted inflammation	Varies by personal health needs

Choosing the Right Supplement for Your Needs

The choice depends on your health goals. Cod liver oil is suitable for general wellness, bone health, and immune support, especially if you need vitamins A and D. A standard omega-3 supplement is better for a targeted, potent dose of EPA and DHA for heart or brain health, particularly if you want to avoid extra vitamins or the risk of vitamin A toxicity. Consult a healthcare provider before starting either supplement, especially if you are pregnant, breastfeeding, or taking blood-thinning medication, as omega-3s can affect blood clotting and cod liver oil has high vitamin A.

Conclusion: Tailoring Your Supplement Choice

Choosing between cod liver oil and omega 3 depends on individual needs. Understanding their differences in source, vitamin content, and omega-3 concentration is key to making an informed decision. Always consult a healthcare professional before starting any new supplement.

Visit the National Institutes of Health website for more information on omega-3 supplements

Frequently Asked Questions

The main difference is that cod liver oil contains vitamins A and D in addition to omega-3s, while standard omega-3 fish oil supplements are processed to contain a higher, more concentrated level of just the omega-3 fatty acids EPA and DHA.

It is generally not recommended to take both simultaneously due to the potential risk of consuming excessive amounts of vitamin A, which is present in cod liver oil and can be toxic in high doses.

A standard omega-3 fish oil supplement is often considered better for heart health because it offers a higher, more potent concentration of the specific omega-3s (EPA and DHA) that have been studied for their cardiovascular benefits.

Pregnant and breastfeeding women should be cautious with cod liver oil and consult their doctor. The high concentration of vitamin A in cod liver oil can be harmful in high doses, so a more targeted omega-3 supplement might be a safer option.

Unlike water-soluble vitamins, vitamin A is fat-soluble and can accumulate in the body. Excessive intake over time from high-dose cod liver oil can lead to toxicity, causing symptoms like headaches, dizziness, and even liver damage.

Yes, plant-based alternatives include omega-3 supplements derived from algae, which contain beneficial EPA and DHA, and flaxseed oil, which contains ALA that the body can convert into EPA and DHA.

Consider your primary health goals. For general wellness and bone health, especially with low sun exposure, cod liver oil is an option. For targeted heart and brain health benefits without the added vitamins, a concentrated omega-3 fish oil is better. Always discuss your choice with a healthcare provider.